Fig. 3. Main discriminant characters between females of Psenulus fulvicornis (Schenck, 1857) and P. schencki (Tournier, 1889). (A) Propodeal surface and (B) pygidial area of P. fulvicornis from the City of Zurich, Switzerland (D. Frey & A. Zanetta leg.; M. Řiha det.; R. Neumeyer conf.; WSL coll; GenBank accession Nr. KY039438). (C) Propodeal surface and (D) pygidial area of P. schencki from the City of Zurich (25.05.2015; D. Frey & A. Zanetta leg.; M. Řiha det.; R. Neumeyer conf.; WSL coll; GenBank accession Nr. KY039439). In P. fulvicornis, the lateral surface of the propodeum (A) has short crosswise carinas which gives the texture coarse appearance. This character is unique among females of Central European Psenulus. In P. schencki such crosswise carinas are lacking (C), and the texture is finer. The pygidal area is longer and broader in P. fulvicornis (B) than in P. schencki (D), but this character can be difficult to observe in certain specimens.

Published as part of Frey, David, Gayubo, Severiano Fernández, Mokrousov, Mikhail, Zanetta, Andrea, Řiha, Martin, Moretti, Marco & Cornejo, Carolina, 2019, Phylogenetic notes on the rare Mediterranean digger wasp Psenulus fulvicornis (Schenck, 1857) (Hymenoptera: Crabronidae) new to Switzerland, pp. 27-42 in Revue suisse de Zoologie 126 (1) on page 33, DOI: 10.5281/zenodo.2619514